Carburetor



July 7, 1931. R, sHlPMAN Y 1,813,206

' GARBURETOR F'iled July 1.192'7 2 Sheets-Sheet l CARBURETORv Filed July1, 1927 2 sheets-sheet 2 gwoon-to@ Ithiman RALPHJYSHIPVMAN; F11SUNBURY," PENNSYLVANIA cmuamoa,

. Application mea Julyi, 1921.. Barnim. 1102.941.y

This.inyenti on. ,has v:for its, ob]`ect f to pro.- vide.a;con struction;in, carburetors by .which is accomplished a ifto.; or: apart afrom-.the abovei v`yailichjokefadjficent to the znozz stru theseveral 2fallar..descri` nyention,7 g further consists-.in the. conf.y

Referring-tothe accompanying drawings intwhichcorrespondin 4parts.are...designated g by,corresponding mar s of Jreference':

Figurelisa verticalsectionpartly in,eleva.

1re- 2fis'afvertical sectionof parts shown ind?.y re.-;1;withithecasingremovedre.3 isaview similar lto Figure 2, but

-.pnff-.angjenlarged vscaleandfwlth vcertain parts .4A isaplan view. ofthe .fuel nozzle 511....:l

bro

vne 5 fis. `afside relevation thereof. 30,@ Laiska. side view ofthe airchoke sleeae ndi itsfassociated weight.

'is a-.plan view lof the parts shown in-,Flg'lll Figure 8 is a detailvrepresenting the man- 35 ,ner of. mounting ofthe metering pin. v

Referring-,to the drawin 1 lrepresents a suitable carburetor casing,orming a mixin chamber, having mounte n which', is to be connected tothe manifold of tothe/en ne, the throttle 2 in the form of a butteri7and having about midway of its height arestriction forming a Vsto forthe member to be hereinafter described, and

preferably forming the seat 3 ofv an air valve,

15 to be, hereafter described. The mixing chamber casing below the seat3 is connected to an. air intake 4, having the.usual choke 5 therein,the bottom of the casing being provided-with a fuel intake 6 which leadsfrom 50 the .usual float chamber 7 to a gasoline nozzle desiredvcontrol. of the. fuel.: mixture. Fior thisgpurpose. I provide f means,whelgebydhei Qsifion of iai-'fuely throttlingele.-l "ment rin); he..ucl .nozzle.is'controlled ;by the:`

` f^?pressure.:existing.on` opposite.`

sual air throttlesand in, which, t th by, Sissa. aboye.; agspecified:gdeman'dffor. 1 'ainby the. en,-

y controlled- :by such .pressure diierences.

cti0n;,= ,arrangement andfscombination 4of Eartsaswl hereinaftermore Vlcarbure,tor. .embodyingmyinvention.2

'1ower.one,`20b,. and the two being unitedby ear its upper en 8.Thisnozzle enters and extends uprthrough Thenozzlepasses.through asuitable; packing f box l y9 tformedQ .Lonv :the bottom: offth'effcasing, an'd throughl ani. iupwardr' extension. 10- -fa's. l5tened.to. suchf bottom, it lbeingI threaded. finto the latterfo'radjustment;v Wlthin thenozzley is threaded the stem ofmetering pin=13,`fvl1"av4 ingla conical head 14 normally terminating i, belowythetopA of thenozzle.- In onder ftofpre-x.v serve @alignment fof thehead. kon. adjustment, the threaded stem "is" connected. byi a.ball-fand-il socket joint showngat- ;15.in Figure-3 w-ith.l the.conical head of zthepin;

annular', terminates `slightly'below-the nozzle 8,and forms -theseatIfor `an air choke sleeve, it having notches 16 in its upperAouter-edges toI assfa limited. 'quantityxofv air at all times-.-4

ithinthe u per part of the mixinglzch'am-z ber;is contained `amemberf20I shown: as cone 1 sisting 4.oftwo cylindrical parts, the upperone, 20a, beingk of greater diameter than the a tapering portion 20cwhich cooperates with.y andseats upon ythe seat 3 in the mixing'Jchamber.l Theupper portion of this member-20 is hollow .and forms acylinder whosefunction will be describedflater. The member 20 is guided.for movement byhaving its-lower 80 l portion20b enterin the .upper endvof afper` forated shield 24 -w 'chzrises from the base of the carburetorandsurrounds the fuel nozzle and the extension10,.being,spaced some--what therefrom.L Also for the purpose 'of guiding the member 2O itsupper endreceives a piston head 21 fast on a tubular `guide v22,whoseupper end is ysleeved. on the throttle shaft 23,therguidecxtendingw'throu hsthe upper vhead 25 of themember20.- eairpassage 26 within the tube hasv its u per end communicatingy with .thespace vva ove` the throttle, such communication being control# led by aballcheck valve 27 The Vhead 25 of the member 20` is threaded ontothecircumferential walls vthereof to-permit the assem. blage within themember of jdesired parts, a spring 30 beinginterposed betweensuch headand the piston head. This spring serves to carry the weight of themember 520;.and-

The upperend of.theiextensionalfwhichis 05 fold and the metering-tubemoves u parts mounted thereon, and when the engine is not running,maintains the member slightly o' the seat 3. The space between the head25 and the piston head is in communication with the bore 26 of thetubular guide through a port 31 of restricted dialneter'in the wall ofthe guide.

An annular shoulder32 is formed within the upper cavity of the member 20and is threaded to receive the plug 33 which forms the lower head forthe cylinder in which the piston head 21 is contained. The plug has anannular flange 34 on its upper face, within which is received a secondpiston head 35 on the upper tubular end of a piston 36, the lower end ofwhich terminates in a tube 36a which enters the upper end of the nozzle,and at about the level of the end of the nozzle is tapered. The uppertubular end of the piston 36 receives t-he lower end of the tubularguide 22 through a suitable self-centering packing box. Thisself-centering packing box may consist of a washer 37 snugly surroundingthe tubular guide 22 and held within a cavity 38 in the top of thepiston 36. The interior cavity at the top of the piston 35 communicateswith the central bore 26 of the guide and through ports with the s acebelow the piston head 35, so that in sucii last named space also existsthe same pressure as exists in the manifold. The annular shoulder 32 hasports 40 therein communicating with the space within the base of theenlarged portion 21 of the member-2O and such space communicates withthe space exterior of the member through peripheral ports 41, so thatwhile manifold ressure exists in the space above the piston ead 21 andbelow the piston head 34, the space between thepiston heads has mixingchamber pressure within it. Hence the member 20 moves up and down as awhole in response to the variation of differences of pressure in themixing chamber and the maniand down in respect to the member 20 inresponse to the same variation of ressure, a spring normally lifting thep1ston head to its upper limit of movement.

A shoulder 42 is formed on the interior of the member 20 at about theupper end of the -lower portion thereof, and serves as a su port for theannular weight 43 for the air choke sleeve and which has a correspondingengaging shoulder 44, by which such Weight member is carried in themember 20.

The lower end of the weight surrounds the upper reduced end of theannular air choke sleeve 45, the bottom of which is interiorly taperedand surrounds and cooperates with the upper end of the primary air valveseat formed on the top of the extension 10. The sleeve 45 thus surroundsthe` tube 36a which enters the fuel nozzle and which has perforasleeve,where it is mixed with aid which has passed the air choke, and whichpasses through the central bore of the weight 43 to the peripheral ports41,

AIn order to prevent this passage being closed at such times as theweight member 43 is lifted from its seat by the sleeve, the for Vmer hasits upper end notched as at 47.

The general operation is as follows:

When the engine is not running, the parts are in the position shown inFi res 1 and 2, that is to say, the member 20c 1s slightly off the seat,3 and has lifted the weight 43 off the air choke'sleeve which is restingon the fuel nozzle 10. The' secondary iston 35 is held raised within'themember 20 y its spring 60.

If the engine is running idle with the throttle more or less closed, thedifferences in pressure existing in the manifold and in the mixingchamber below the throttle willby the excess of the latter pressure overthe former, depress the secondary piston and lower the tube 36a with aconsequent reduction in the fuel fiovv areabetween it and the nozzle 8,fuel beingasperated through such area by the air passing through thenotches 16 in the edge .of the fuel nozzle. The pressure dierence als'ocauses the member 2O to descend and seat on the seat 3 but the weight 43will not be at this time in contact -with or rest on the air chokesleeve. As the engine increases its demand for air, the air drawn upthrou h lthe notches 16, will drag ,with it the air cho e sleeve,increasing the iow area for the air.

At sometime in its movement, this sleeve will contact with its weight 43and its movement will then be dependent not only on its own wei ht buton the mass of the weight.

lpon a further opening of the throttle to increase the engine speed thepressures on the two sides of the butterfly tend to equalize so thatthespring 30 vis enabled to lift the member 20, thereb unseating themember from the seat 3 an at the same time lifting the weight 43, thisenabling the choke sleeve to resume`its free movement untilagain-retarded by the weight.

The differences of pressure may still vbe suiiicient to compress thespring 60 and to hold the secondarypiston 36 down. As the throttle isstill further opened with the consequent greater equalization ofpressure on both sides of it, the spring 60 comes into action to liftthe secondary piston 36 and in consequence to increase the fuel iiowarea around the tapered end 36a of that piston. On a reverse actuationof the throttle the reverse movements occur.

In order to retard the movements of the member 20 and the secondarypiston 36, and to prevent an abrupt change in fuel condition before theengine has had an opportunity to respond to the change in position ofthe throttle, the check valve 27 is employed.

Upon the opening of the throttle there immediately results an`abruptdecrease in the vacuum (increase of pressure) in the 4manifold with anincrease of vacuum (decrease of pressure) in the mixing chamber. Uponthe increase of pressure in the manifold over that existing between thetwo piston heads 21 and 35, the ball 27 will seat, trapping above thepiston head 21, and below the piston head gases under the pressure whichhad existed in the manifold prior to the opening of the throttleandhence more or less nearly equal to the new conditionof pressureexisting in the mixing chamber. Hence the elements above described,which depend for t-heir action upon the pressure differences, are forthe time being rendered inert and this inert condition will continueuntil leakage restores them to their previous Arelative condition ofpressure. In order to prolon this period, without making such close tsas` would induce friction, I may, as shown in Figure 1, provide a vacuumchamber 66 exterior of the carburetor but connected to the central bore26 of the guide 22 through the pentral bore 67 in the shaft 23 of thebutteryAs a convenient and eilicient device for manually varying thefuel supply, the metering pin 14; is employed. By lowering this pinso-that its tapered head becomes oppositethe lower end of the tubularbase of the piston 36a the supply of fuel to the interior of such pistonmay be controlled and hence the flow offu'el from the ports 36?) in suchpistonI `under the pull of the air iowing through `the air choke sleevemay also be controlled.

. Having thus described my invention what I claim is 1. In a carburetorthe combination of a mixingl chamber, a fuel nozzle therein, a

throttle near the exit end of the mixing chamber, an air choke sleeveadjacent to the nozzle and an air valve whose position is determined bythe differences of pressure on opposite sides of the throttle and whichcontrols the area of the air choke and also the area of an air passagein the mixing chamber but remote from the nozzle.

2. In a carburetor the combination of a mixing chamber, a, fuel nozzletherein, a throttle near the exit end of the chamber, an air chokesleeve surrounding the nozzle and restricted fin itsmovement by ayielding abutment and means actuated by difference of pressure onopposite'sides of the throttle for controlling the position of theabutment.

3. In a carburetor `the combination of a mixinof chamber, a fuel nozzletherein, 'a throttle near the exit end of the chamber, an air chokesleeve surrounding the-nozzle and Y movable under the flow of airthrough the same, a yielding member restricting the movement-of thechoke' sleeve and means aotuted by difference of pressure on oppositedouble headed cylinder in the mixing sides of the throttle forcontrolling the position of the yielding member.

4. In a. carburetor, the combination of a mixing chamber, a fuel nozzletherein, a throttle near the exit end yof the chamber, an elementthrottling the nozzle, a cylinder, a piston head shiftable there-in bythe pressure vdifferences above and below the throttle and differencesabove and below the throttle and controlling the movement of the fuelthrottling element, means controlled by the pressures above and belowthe throttle for shifting the cylinder and piston head therein, an airchoke sleeve surrounding the nozzle and means actuated by the cylinderfor controlling the movement of the air choke sleeve.

6. In a carburetor the combination of a p mixing chamber a fuel nozzletherein, a

throttle near the exit end of the chamber, a

double headed cylinder in the mixin chamber, a fixed piston head nearone end of the cylinder, a movable iston head near the op posite end ofthe cy11nder,the space between ythe pistons communicating with themixing chamber below the throttle and the spaces between each piston.and the adjacent end of the cylinder communicating with the space abovet e throttle and a throttling element for the fuel controlled by themovable iston head.

7. In a carburetor the com ination o-f a mixin chamber, a fuel nozzletherein, a

loc

,thrott e near the exit end of the chamber, a

charnber, a fixed piston head near one en of the cylinder, a movableiston head near the opposite end of the cylmder, the space between thepistons communicatin with the mixing chamber below the throttle and thespaces between each piston and the adjacent end of the cylindercommunicating with the space above the throttle, a throttling elementfor the fuel controlled by the movable piston head, and an air cho esleeve surrounding the nozzle and controlled by the movement of thecylinder.

.8. n a carburetor, the combination of a mixing chamber, a fuel nozzletherein, a throttle near the exit end of the cylinder, a double headedcylinder and a piston contained in the mixing chamber, one of the saidelements being fixed and the other movable, a second pist-on head in themovable element, the s ace between the second piston head and the xedelement communicating with the mixino chamber below the throttle and thespace between the first piston head and the cylinder and between thesecond piston head and the moving element communicating with the spaceabove the throttle and aA metering element controlled by the secondpiston hea-d.

9. In a carburetor, the combination of a mixing chamber, a fuel nozzletherein', a throttle near the exit end of the cylinder, a double headedcylinder and a piston head contained in the mixing chamber, one of thesaid elements being fixed and the other movable, a second piston head inthe movable element, the space between -the second piston head and thefixed element conununicating with the mixing chamber below the throttleand the space between the first piston head and the cylinder and betweenthe second piston head and the moving element communicating with thespace above the throttle, a metering element controlled by the seco-ndpiston head, and an air choke controlled by the movement of thecylinder. y

l0. In a carburetor the combination with a mixing chamber, a fuel nozzletherein, a throttle near the exit end of the chamber, a, cylinder Withinthe-chamber, a piston head within the cylinder, one of the last twoelements being movable, the space vwithin the cylinder being incommunication with the space above the throttle, a check yalvecontrolling such communication, means for controlling fuel mixturecontrolled by the movement of the movable element, and a vacuumreservoir exterior of the carburetor and connected with the space withinthe cylinder.

In testimony whereof I hereunto aix my signature.

RALPH SI-IIPMAN.

